[Parameters for determining the effective treatment pressure in nCPAP therapy of sleep apnea].

We evaluated the accuracy of single parameters from the polysomnography in establishing the effective nCPAP treatment pressure in order to possibly economize pressure adjustment. In four patients (pts) a standard polysomnography was performed. 67 segments of 30-60s in duration, showing different typical types of breathing disturbances or normal breathing were selected. The segments were divided into 5 horizontal parts consisting of only one of the following signals: SaO2, snoring, mask pressure, esophageal pressure (Poes) and respiratory movements (RC + Abd). A second investigator then classified these 335 one lead recordings without knowing the complete segment. The classification based on the complete segment compared to that based on only one parameter gave an identical result in 44.8% (SaO2), 61.2% (Poes), 64.2% (RC + Abd), 80.6% (sonoring) and 82.1% (mask pressure) respectively. 97% of the complete segments were classified identically by both investigators. Each of the studied parameters alone was not adequate in establishing the correct pressure level. SaO2 corresponds least, mask pressure and snoring best to the classification based on all parameters.